Fresh fighting in eastern Ukraine has forced an international forensics team to halt operations in part of the vast crash site of Malaysian flight MH17.

Observers had to withdraw from one village when they heard artillery fire although work is still continuing across much of the area.

MH17 went down on 17 July with the loss of all 298 passengers and crew.

The US and Ukraine say pro-Russian rebels probably shot down the jet with a missile but rebels deny the claim.

Sniffer dogs

Alexander Hug, the deputy chief monitor with the Ukraine mission of the Organization for Security and Cooperation in Europe (OSCE), told Agence France-Presse a visit to the village of Petropavlivka had been agreed with the rebels and Ukrainian forces.

However, he said: "We heard at a distance of approximately two kilometres incoming artillery from where we were and that was too close to continue."

However, the BBC's Jonathan Beale, at the crash scene, says there has been no fighting at the main site and the experts have been able to do their work.

Media captionThe investigators released footage from their first full day of searching at the crash site

Image copyrightGraham HillImage caption
Pro-Russian rebels have blown bridges along the route to the crash site, to slow any advance by Ukrainian forces

Image copyrightReutersImage caption
Neither Ukrainian forces nor rebels are in full control of the crash site

About 70 Dutch and Australian experts are scouring a site of some 20 sq km.

A spokesman for the Dutch team said it was still focusing on searching for human remains, although security is also a key issue.

Neither the rebels nor Ukrainian forces are in full control of the site.

The Dutch team has flown in from the Netherlands two dogs trained to search for human remains and another two specialist dogs are on their way from Belgium.

Our correspondent says the Australian team also has specialist equipment - a mini-drone fitted with a camera - but it has not yet been given permission by the rebels to fly it.

The US and Ukraine say pro-Russian rebels probably shot down the plane with a missile supplied from Russia.

The rebels say it could have been brought down by a Ukrainian fighter jet.

Most of those who died were Dutch nationals.

More than 220 coffins have now been sent back to the Netherlands.

'Highly disciplined'

Separately, a senior adviser to the rebels confirmed that extrajudicial killings had been carried out in eastern Ukraine "to prevent chaos".

Image caption
Mr Druz said Ukraine's government was a "terrorist" organisation

Igor Druz told the BBC such "executions" sent an important signal to the rest of the rebel forces.

Mr Druz told the BBC: "On several occasions, in a state of emergency, we have carried out executions by shooting to prevent chaos. As a result, our troops, the ones who have pulled out of Sloviansk, are highly disciplined."

Sloviansk was a key rebel stronghold before it was recaptured last month by Ukrainian government forces.

Analysis: Dina Newman, BBC News, Donetsk

Igor Druz is adviser to the rebels' military commander Igor Strelkov, and a senior spokesman for the rebel-held territories of Donetsk region. He is in charge of the ideology of the eastern Ukrainian rebel movement. In an interview with the BBC in Donetsk he outlined his vision of the so-called 'state of Novorossia' they hope to build here.

He says he is a strong supporter of Orthodox Christian morality and family values, and opposed to homosexuality. He hopes to legalise death penalty for the most serious crimes and he is sure that most rebels will support him in this initiative.

Mr Druz said the rebels wanted to establish a socially responsible state that would protect Christian values.

He also said the Ukrainian government was "totally illegitimate".

Mr Druz said: "These people have come to power by committing murders and staging an armed coup. Now they are committing war crimes. They are bombing our cities. They shell cities and then blame it on our fighters. This is nonsense."

More than 1,500 people are believed to have been killed in the conflict which erupted in east Ukraine in April, after rebels declared independence from the new government in Kiev.

Russia, which annexed Ukraine's Crimea region in March, has been accused of arming the rebels and has been targeted by US and EU sanctions. Russia denies the accusations.